Modern Pistons

AL in NY

AL in NY

Well-known member
I'm in the middle of a new engine build and I'm contemplating using modern Chevy 302 4.000" pistons. Besides being lighter, want are some advantages/disadvantages to doing this upgrade?
 
AL in NY said:
I'm in the middle of a new engine build and I'm contemplating using modern Chevy 302 4.000" pistons. Besides being lighter, want are some advantages/disadvantages to doing this upgrade?
Click to expand...

Isn't the wrist pin height wrong for 302 pistons? You can buy 283 pistons that are made for model A's. You can get .125 over size that will give you a 4" bore.
 
Try talking with Rich Falluca, Antique Engines, in Skokie, IL. He has a lot of experience with those pistons. Gar Williams
 
Why the 302 pistons? A stock 302 piston has a large dome and would most likely require a lot of work to clear the head.
You could also raise the compression ratio quite a bit.

Maybe that's the idea.
 
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John,

The 283 pistons come in bore sizes to .125, and are flat tops. Yes, the 302's do
come with a dome. Confusion in the ranks?

Dudley

PS....I thought some guys were using ford 302 also.......I guess I should do some
studying on the compression height distance.
 
The reason for the 302 pistons, same compression height as 283 but in 4.000" bore. Have been unable to locate 283's in .125" over. The thread was to inquire about advantages vs. disadvantages of using the more expensive modernskirted pistons verus the standard model A piston. My first thoughts were less fiction, less heat, more HP. Is my thinking wrong?
 
A newer piston should give you more ring choices as far as thickness I would think as well. If you use a domed piston at least you can mill it to exactly what you want to match up with your motor and head specs also.
 
Weren't some folks using 352 Ford pistons?? If you do use the Chevy pistons don't you always have to add some kind of anti-rejection medicine ??
 
I have a rebuilt engine done by Rich Falluca of Antique engine rebuilders in Skokie Illinois ...It has the Chevy pistons they are flat top and I noticed they have the little Valve cut outsor indentations in the top of each piston ...The engine runs great !

B0b in Michigan
 
AL,

If you know the combination works, have at it, you are correct about the friction,
and horsepower, if the piston is lighter. Better ring combination, plasma moly top
ring with a moly finish on the bore.

Dudley
 
d.j. moordigian said:
John,

The 283 pistons come in bore sizes to .125, and are flat tops. Yes, the 302's do
come with a dome. Confusion in the ranks?

Dudley

PS....I thought some guys were using ford 302 also.......I guess I should do some
studying on the compression height distance.
Click to expand...

I though you were talking about 302 chev engine. The 283 piston I'm talking about are made with the right wrist pin height. Plus they have a 1" wrist pin and you do not have to trim the rods.
 
AL in NY said:
The reason for the 302 pistons, same compression height as 283 but in 4.000" bore. Have been unable to locate 283's in .125" over. The thread was to inquire about advantages vs. disadvantages of using the more expensive modernskirted pistons verus the standard model A piston. My first thoughts were less fiction, less heat, more HP. Is my thinking wrong?
Click to expand...

Stock 302 or 283 chev pistons have the wrong piston pin size they .927 they also have the wrong piston pin height. If you use with stock rods the top of your piston will be about .200 below deck.
Or you can do like I did and make new rods from 7075 alum.

But I have used the 283 styl piston that John Casper sells. hope I got his name spelled right. They fit right from the box, if you get the latest ones.
 


Hi guy's


When I bought my "B" short block it came with 57 "Old's" 371 piston's.. The block was bored out to 4" and The rod's have special bushing as the pin's are .980.. Guy said someone back about 1960 was going to make a dirt track racer with it..


I just went ahead and used it the way it was...So far so good...


I'll bet old "Henry" would be all upset upound hearing this,,,GM part's in my motor's !!!


Greg out West,
 
The "B" engine I am assembling will use the 352 Ford ohv V-8 pistons. Wrist pins are a fit but the pistons set down the bore a little. In my block they are are down .020, I don't know if this block has been decked or not and in my case it doesn't matter but it may be a factor in someone else's buildup. Personally I was hoping for something down the bore around .040 but I will work with what I have. This engine will be running a Thomas head that I have yet to cc, with a head gasket crush of .050 and .020 down the hole, maybe a bare minimum clearance. After cc' ing I may have to do a little machining. The advantages I see to the "slipper" pistons are maybe a little better and stronger design thru modern engineering, thinner rings, modern ring material and improved wrist pin retainer design. This week I have seen a "B" engine that lost two retainers, one on each of two pistons. Don't know what caused the problem, maybe bent rods, but we never ran those round wire retainers in our blown fuel engines, even before we went to teflon buttons
 
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